1. Field of the Invention
The present invention relates to an actinic-ray- or radiation-sensitive resin composition that can find appropriate application in an ultramicrolithography process applicable to the manufacturing of a super-LSI or a high-capacity microchip, etc. and other photofabrication processes, and further relates to an actinic-ray- or radiation-sensitive film from the composition, a method of forming a pattern, a process for manufacturing a semiconductor device, a semiconductor device and a novel compound.
2. Description of the Related Art
Heretofore, the microfabrication by lithography using a photoresist composition is performed in the process for manufacturing semiconductor devices, such as an IC and an LSI. In recent years, the formation of an ultrafine pattern in the submicron region or quarter-micron region is increasingly required in accordance with the realization of high integration for integrated circuits. Accordingly, the trend of exposure wavelength toward a short wavelength, for example, from g-rays to i-rays and further to a KrF excimer laser light is seen. Further, now, the development of lithography using electron beams, X-rays or EUV light, aside from the excimer laser light, is being promoted.
In the development of such lithography technologies, various proposals have been made on, for example, photoacid generators incorporated in photoresist compositions (see, for example, patent references 1 to 3). In particular, the lithography comprising exposure to electron beams, X-rays or EUV light is positioned as the next-generation or next-next-generation pattern forming technology. Positive resists of high sensitivity and high resolution are required for this lithography. Specifically, increasing the sensitivity is a very important task to be attained for the shortening of wafer processing time. However, the pursuit of increasing the sensitivity is likely to cause not only the lowering of resolving power but also the deteriorations of pattern shape and line edge roughness. Thus, there is a strong demand for the development of resists that can simultaneously satisfy these performances. Herein, the line edge roughness (LER) refers to the phenomenon that the edge at an interface of resist pattern and substrate is irregularly varied in the direction perpendicular to the line direction due to the characteristics of the resist, so that when the pattern is viewed from directly above, the pattern edge is observed uneven. This unevenness is transferred in the etching operation using the resist as a mask to thereby cause poor electrical properties resulting in poor yield. Especially in the ultrafine region of 0.25 μm or less line width, the line edge roughness is now an extremely important theme in which improvement is to be attained.